In recent years, the arithmetic capability and the communication speed of information processing devices have been rapidly enhanced. However, in a relatively small-sized information processing device such as a portable terminal, for example, since the size of a display unit which displays processing results is limited, there are cases where the quantity of information to be displayed is restricted and high performance as described above is not fully utilized.
Thus, a technique for making effective use of a display unit of an information processing device has been developed. For example, there is a technique in which a touch panel is provided in the display unit to secure operability and expand the display unit. JP-A-2010-109552 and JP-A-2009-009252 disclose a technique in which pushing conditions of a touch panel are used as operation inputs.
In addition, there is a technique in which changes in the state of a housing of an information processing device are used as operation inputs, and various operation inputs are realized without reducing the size of a display unit. JP-A-2004-334642 discloses a technique in which application of shaking to a housing is used as an operation input. JP-A-2005-245619 discloses a technique in which inclination of a housing is used as an operation input.